2001 E53 M54 Fuse 61 drawing 2.5a after sleep mode 16 minute?

[Cora]

Hello. I have completed a parasitic draw test on my wife's 2001 bmw e53 m54 X5 (third owner at 142k, now 148k) and determined that the fuse placed in cabin fuse 61 (main fan, 50a fuse) is drawing 2.5a after the 16.5 minute sleep cycle time. With fuse 61 removed vehicle draw is 0.02a. I have replaced the suggested Final Stage Resistor with a genuine BMW Behr oem FSR and the draw continued. Visual inspection shows previous FSR was new version that previous owner may have had replaced and no bulging or reference to issue by sight. The harness did not appear to be damaged or contain corrosion. The battery was just replaced with Duralast Gold suggested on this board. I have been reading posts about issues with battery drain here and other boards and all suggest the FSR is the issue.

I am thinking to test the grounding through the circuit for short? Also want to note this is not my daily driver. I only fix lol. When I started the vehicle after the new battery install and resting overnight, the main and aux fans both turn on. Aux should have a threshold to kick on, but again, I do not know for this vehicle. Average temp outside is 90 degrees so this may also suggest why it does? I have read about aux fan becoming issue, but that blows fuse from my understanding?

My questions are as follows:
What should resting draw from circuit 61 be?
Does anyone have the schematic to share for circuit attached to fuse 61?
Any suggestions?

[andrewwynn]

Wow 36w consumption would be enough to be quite warm. Too bad it's so friggin warm where you are or you could simply pass your hand around the car or use an IR thermometer to locate the power drain. Maybe if cool at night pull the fuse overnight and plug back in at the coolest part of the day. Within a couple hours whatever part drawing 36w should be 10-20°F hotter than ambient and easy to find with IR thermometer.

If you have a spare FSR I'm pretty sure my wife's just died. I could use it


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[Cora]

So I traced the circuit hand over hand. Main harness to main fan had a home job wire spliced in to power wire and the other end was spliced in to air conditioning compressor. Removed and resting amp is now 0.02. Now air compressor is not getting current to start air compressor when key in motor on. Looking through the posts I see suggestions that auxiliary secondary fan may be suspect. 50 amp fuse in circuit 61 is fine no indication of over current draw. Aux fan does run with home wire removed. Now my question is is there a relay preventing delivery of current to clutch circuit in compressor? I checked high and low pressure and 45 on low and 250 on high running with compressor direct to 12v battery source. Took test jumper off after of course. So again looking to know if anyone has had issue with aux fan senor not delivery current or aux fan relay in fan (read some say that is where relay lives for fan) still working fan but preventing ac clutch from operating? Thank you.
And thanks for offer on spare part but will hold as I am the type to have a spare motor in shop just in case lol. And for the record, troubleshooting this is actually pretty fun. Usually I'm elbows deep in diesels so nice to deal with just electronic issue lol.

[Cora]

Was thinking this troubleshooting guide would be near what I need to do. Thoughts?BMW Auxiliary Engine Cooling Fan – Testing and Diagnosing How To | Bavarian Autosport Blog

[g300d]

Ugh, we're the opposite...give me a mechanical troubleshoot over an electronic troubleshoot lol!

That fuse provides constant 12v to the fan at all times even with the ignition off. A third signal wire from the DME turns the fan on and varies speed.

But if the AC clutch was wired to that circuit it would be on all the time which may be the drain you are seeing. But key position would not affect this, it would be engaged all the time.

[g300d]

That 50a fuse is for the auxilliary fan.

As I understand it he was saying he tried replacing the FSR as the his research told him it was a common cause of current drain, but it didnt work so he checked some more and found the wire to the AC compressor.

He did mention that disconnecting the wire removed the drain. The magnetic clutch seems to be the one drawing current then.

[Cora]

Sorry if was not as clear as hoped. Did replace fsr just based on suggestions I read. But the actual issue is a home made jumper linking a blue color hot 2.5a wire from main fan/aux fan harness to black/slate wire running to air conditioning compressor. It was the culprit. When installed the air conditioning does work and temp controls function as desired. When jumper is removed no air conditioning compressor and no cold air.

I am trying to learn what the blue wire on this harness is actually for? When the two wires the jumper connects make connection the clutch on the air compressor clutch engages and you hear a click. This is with key off after 16 min.

I am now trying to figure out what is preventing the normal activation of the air compressor when jumper is removed.

Final note. Vehicle amp draw after 16 min is 0.02 with jumper removed.

[g300d]

Ok, guess I understood you correctly then. Good job finding that jumper and solving your current drain!

To clarify, is the clutch engaged all the time until you disconnect the jumper wire? Or with the jumper attached does the clutch click and draw power only when the car goes to sleep?

[Cora]

Anytime the jumper is connected the clutch engages and draws.

[g300d]

Ok. I assume you've checked the other fuses? The AC compressor clutch has its own fuse somewhere there.

Here's a vid that might help you out:
X5 AC system troubleshoot vid